Preheat the oven to 350° F and place a silpat or a sheet of parchment paper on baking pan.
Combine the flour, baking soda, baking powder and salt in a medium bowl and whisk it a few times to thoroughly distribute the baking soda and powder through the flour. Set aside.
In the bowl of a standing mixer fitted with a paddle attachment, beat the softened butter for two to three minutes so that it's lightened in color and fluffy. Add the sugars and peanut butter and beat to completely mix and add the egg and vanilla extract, and continue to beat for another two minutes for a crispier cookie. For a chewier cookie, please refer to the Cook's Notes above.
Fold in the dry ingredients gradually on the lowest setting of your mixer, or by hand. Fold in the oats and chocolate chips by hand.
Using an ice cream scooper, scoop the dough onto the prepared baking sheets. Bake for 8 - 10 minutes.